Greece: 3 August Deadline Marks Final Window for E-Invoicing Tax Incentives Ahead of 1 October Mandate

Summary

Greek entities falling under the second implementation phase of the country’s mandatory B2B e-invoicing regime had to begin issuing invoices exclusively in electronic form and submit the corresponding declaration by 3 August 2026 in order to preserve early-adoption tax incentives. This deadline fell two months ahead of the mandatory 1 October 2026 start date for phase-two entities, under the framework set out in AADE Decisions A.1128/2025 and A.1129/2025, published in the Official Gazette on 16 September 2025.

The incentives, introduced under Article 71Θ of the Greek Income Tax Code (Law 4172/2013), reward businesses that voluntarily adopt exclusive e-invoicing ahead of their mandatory deadline with a 100% enhanced depreciation allowance on the initial acquisition costs of hardware and software needed to implement e-invoicing, recognized in the year of purchase, together with a 100% increased deduction for the costs of producing, transmitting and archiving e-invoices during the first twelve months of operation.

To claim the benefit, phase-two entities relying on certified e-invoicing providers had to submit their declaration under the procedure set by Decision A.1112/2025, while businesses opting to use AADE’s free “timologio” application had to file the Electronic Data Issuance Initiation Statement via myAADE within 10 days of starting exclusive electronic issuance, and in any case no later than 3 August 2026, ahead of the 1 October 2026 mandatory start date.

Legal and Regulatory Background

Greece’s business-to-business (“B2B”) e-invoicing mandate is being phased in under Article 14 of Law 4308/2014 (Greek Accounting Standards – ELP), as amended by Article 239 of Law 5222/2025, following EU Council Implementing Decision (EU) 2025/502 of 5 March 2025, which authorized Greece to derogate from Articles 218 and 232 of the EU VAT Directive (2006/112/EC). On 16 September 2025, the Deputy Minister of National Economy and Finance and the Governor of the Independent Authority for Public Revenue (“AADE”) jointly issued Decision A.1128/2025, defining the scope, effective dates and general conditions for mandatory e-invoicing, while AADE issued Decision A.1129/2025 in parallel, setting out the procedure and deadlines for submitting declarations of use of e-invoicing, including the conditions to benefit from the early-adoption tax incentives.

Sources: AADE Decision A.1129/2025; AADE Decision A.1128/2025 (PDF)

1.1. Two-Phase Mandatory Rollout

The mandatory e-invoicing regime applies to domestic B2B transactions between entities subject to Greek Accounting Standards, to B2B sales of goods and services to non-EU established businesses, and to business-to-government (B2G) transactions. Intra-EU B2B transactions remain optional for e-invoicing. The mandate is being implemented in two phases:

Phase 1 (large enterprises with gross revenue exceeding €1,000,000 in FY2023): mandatory exclusive e-invoicing since 2 March 2026 (postponed from the originally announced 2 February 2026), with a transition period running to 3 May 2026.

Phase 2 (all other entities subject to Greek Accounting Standards, including sole proprietors and small businesses): mandatory exclusive e-invoicing from 1 October 2026, with an adjustment period running to 31 December 2026.

Sources: EY Greece – Mandatory e-invoicing; KPMG – Compliance deadlines for e-invoicing

Early-Adoption Tax Incentives Under Article 71Θ

Article 71Θ of the Income Tax Code (Law 4172/2013) grants tax incentives to entities that opt for the exclusive issuance of e-invoices ahead of their applicable mandatory start date. Decision A.1129/2025 defines the method, deadlines for submitting the relevant declarations, and other implementation matters relating to these incentives. Entities that qualify benefit from:

100% enhanced depreciation of the expenses for the initial acquisition of the equipment and software required for e-invoicing, deductible in the year of implementation; and

100% enhanced deductibility of the expenses related to the production, transmission and archiving of e-invoices incurred during the first 12 months of use.

To qualify, an entity had to belong to one of the following categories: (i) first-period entities (large enterprises) that issued e-invoices and submitted the required declaration by 1 December 2025, at least two months ahead of the original mandatory start date; (ii) second-period entities (all other businesses) that did so by 3 August 2026, two months ahead of the 1 October 2026 mandatory start date; or (iii) entities already using e-invoicing that submitted their declaration before 1 December 2025.

Sources: KPMG – Procedure to claim incentives for early implementation of e-invoicing; ROQ Consulting – August 3 Deadline: Greece’s Mandatory B2B E-Invoicing Is Here

The 3 August 2026 Deadline and Submission Process

For second-period (Phase 2) entities, 3 August 2026 was the operative cut-off date to lock in the incentives described above, falling exactly two months before the 1 October 2026 mandatory start date. Missing this date does not exempt an entity from the underlying e-invoicing mandate, which still takes effect on 1 October 2026 with a transition period through 31 December 2026; it only forfeits eligibility for the enhanced depreciation and deduction benefits linked to early adoption.

3.1. How the Declaration is Filed

Entities using certified Electronic Data Issuance Service Provider (“YPAHES”) services must submit the declaration in accordance with Decision A.1112/2025, by the relevant deadline.

Entities using AADE’s free “timologio” application must submit the Electronic Data Issuance Initiation Statement via the myAADE portal within 10 days of starting use, and in any case by the relevant deadline; selecting “timologio” automatically includes access to the myDATAapp.

The declaration must contain the entity’s identification details, the start date of e-invoicing, the types of transactions covered, and the submission date. A unique reference number is assigned by AADE upon submission.

Sources: KPMG – Procedure to claim incentives for early implementation of e-invoicing; Sovos – Deadlines for Mandatory B2B E-Invoicing Announced

Outlook: 1 October 2026 and Non-Compliance Penalties

From 1 October 2026, exclusive electronic invoicing becomes mandatory for all remaining entities subject to Greek Accounting Standards, with an adjustment period running through 31 December 2026 during which businesses may continue to operate their existing ERP or accounting software in parallel with the new e-invoicing channel. After the transition period, failure to issue a compliant e-invoice is treated as non-issuance of an invoice under the Code of Tax Procedure: for VATable transactions, this triggers a fine equal to 50% of the VAT due on the transaction, while non-VATable transactions attract fixed penalties of €500 to €1,000 per tax audit, depending on the accounting system applied.

Sources: marosavat.com – Greece Introduces B2B E-Invoicing Mandate; VATfaqs – Greece e-Invoicing Mandate 2026